As the title warns, John Cage's 4'33" is four minutes and thirty-three seconds of silence. Soundlessness. Nothing. And yet it is the piece that Billy Bragg, Suggs (yes, him out of Madness) and Orbital, among others, are covering in a bid to keep the latest produce from the X Factor pop-sausage machine off the top of the Christmas charts. As gestures go, it follows the puckishness of John Cage, who premiered his non-playing orchestral piece as a sort of cheeky protest against the boomtime America of the early 50s. And similarly to Cage's piece, the cover is surely destined to be more talked about than played. What a vacuum is to nature, silence is to radio types who refer to it as "dead air". And yet, in a season in which we are bombarded with noise – in-store Muzak while buying those presents, enforced jollity at the work do, and all the rest of that licensed yuletide raucousness – a bit of silence is more than desirable; it is necessary. We make noise to drown out noise: an iPod to muffle other commuters, a bit of EastEnders to blot out a bad day at work, conversation to cover up social discomfort. Yet no yoke joins together the words "awkward" and "silence". Silence is the necessary precondition to contemplation and meditation (religious or not). And the effort needed to achieve even quiet, let alone silence, usually makes it more rewarding than the usual ambient noise. As the writer Garret Keizer points out: "A person who says, 'My noise is my right' basically means 'Your ear is my hole'."